Abstarct: The Hallahan Manganese ore deposite is located in 122 km of south of Damghan, 16 km west of Reshm Village in Torud- Chah Shirin volcano-sedimextary belt and the northern part of Central Iran structural zone. Rock outcrops in the area comprised of mextamorphic complexe such as slate, phyllite, schist, marble, limestone, dolomite and slightly mextamorphed sandstone with lower Jurassic in age. Manganese mineralization in Hallahan area has occurred in main horizon, as stratiform and concordant with beddly. baxsed on mineralogy, structure, texture, structure and relation with the host rocks, mineralization are divided into three different facies: A) vein- veinlet Facies: this facies as a network of veins –veinlets has limit development and undering. B) Massive ore facies: This facies forms thick and high grade of ore deposit. C ) Stratiform Ore facies: thickness of this part of the ore deposit is less than massive ore facies. baxsed on ore microscopy, X-ray diffraction (XRD) and electron microprobe (EPMA) studies the ore mineralogy are mainly pyrolusite, psilomelane, heulandite, braunite and hematite. Spessartine, wollastonite and clay minerals have occasionally been observed with manganese minerals. The main gangues minerals of the ore deposit are quartz, calcite and gypsum. The main structures of the ore deposit consists of laxyered, lentiform, massive and vein structures and the main textures are massive, bandy, vein and veinlet form, dispersed grain, filling the empty space, succession and coliform textures. The existent alterations in the region are Chlorite, Epidote, argillic, silication and carbonatization alterations. Chlorite alteration is the broadest in Halahan region and the hanging and footwall Stones of the ore deposit have intensity chlorite alteration. baxsed on geochemical studies, mextamorphic rocks of the region have the mextabasalt and mextapelitic nature and have been born about the end of the greenschist facies to amphibolite facies beginning. High ratio of Mn / Fe and Si / Al, low levels of trace mextals especially Co, Ni, Cu and high amounts of Mn, SiO2 and Fe are as evidence of Mn enrichment and depletion from submarine hydrothermal fluids (exhalative) in this deposit and exclude the role of hydrogenesis processes and appearance of the ore deposit. Therefore, all the evidences indicate that Halahan manganese ore deposit has been formed under two mechanisms: enrichment in seawater by exhalative hydrothermal fluids and the deposition in sedimentary conditions influenced by changes in Eh and pH in sedimentary environment and it is a volcano sedimentary ore deposit. The features of Halahan manganese ore deposit among formation tectonic environment, 415 geological sedimentary environment, participant host rocks, geometry, mineralogy, texture and chemical evidence, are most similar to the manganese ore deposits of Cuba type, with the exception that Halahan manganese ore deposit influenced by a greenschist facies mextamorphism phase.